Interrupter Size Effect of High-Voltage Gas Circuit Breaker on Thermal Interruption Performance and Current Zero Properties

Small model interrupters are convenient to investigate interrupting performance of high-voltage gas circuit breakers in terms of efficiency. However, the equivalence of interruption phenomena of small model interrupters (e.g., interrupting performance, interruption criteria, and geometric sensitivity) to product-scale interrupters has not been clarified. Interrupting tests with small and large model interrupters were carried out with the dimensions of the interrupter as parameters to clarify the effects of modified interrupter dimensions on blast pressure and interrupting performance. Arc voltage and arc conductance were measured to acquire detailed electrical behavior in the thermal interrupting phase. In the results, small model interrupters showed the same performance trends as geometrically modified large model interrupters. By introducing an interrupter size factor, the boundary of the extinction peak of the arc voltage and arc conductance at 200 ns before current zero that distinguishes the success and failure of interruption for both small and large models agreed well. Moreover, the arc parameters determined by Cassie and Mayr arc models were analyzed with consideration to interrupter size factor. In conclusion, the interrupter size factor was validated from the point of arc phenomena and an equivalence of small model to product-scale interrupter was confirmed. (c) 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.